bug#62720: 29.0.60; Not easy at all to upgrade :core packages like Eglot

[Dmitry Gutov]

On 22/04/2023 14:11, Eli Zaretskii wrote:
> > Date: Sat, 22 Apr 2023 13:30:41 +0300
> > Cc: jporterbugs@gmail.com, philipk@posteo.net, 62720@debbugs.gnu.org,
> >   joaotavora@gmail.com, larsi@gnus.org, monnier@iro.umontreal.ca
> > From: Dmitry Gutov <dmitry@gutov.dev>
> >
> > > Thanks, but this is not what was being discussed, AFAIU.  What I said
> > > I'd agree to is to have package-update accept a prefix argument and
> > > heed package-install-upgrade-built-in (perhaps renamed),
> >
> > I think I explained in the previous email why reusing
> > package-install-upgrade-built-in doesn't seem like a good idea.
>
> And I thought I've explained why I didn't see a need for another
> option.

I also don't see the point of using an option here.

Also think forward to Emacs 30: I think the most reasonable choice would 
be to have package-update upgrade builtins by default, whereas 
package-update-all and package-menu-mark-for-upgrades probably still 
need to be preffed off (not sure, but we won't be able to make the 
choice until later, I think).

But if to make package-update behave properly we need to flip the 
default of the said option, it will flip the behavior of 
package-update-all and package-menu-mark-for-upgrades as well.

> > > and only then
> > > update built-in packages.
> >
> > I asked what plausible scenario you think might be broken by having
> > package-update upgrade builtin package by default.
>
> That's obvious: this is how package-update behaved until now.

That's not an answer to the question.

> > > I also don't think I like the significant changes in package-update,
> > > nor understand why they are needed.
> >
> > Like I said: the changes are to avoid relying on package-install being
> > able to install a package that's already installed. Which currently
> > works only for builtins and when only a user option is set. It's a mess.
> >
> > And to "avoid interdependency".
>
> Why does this have to be in Emacs 29?  It's a cleanup, right?

Not a cleanup, no. If I just keep the previous version of the code, I 
get "package xxx is already installed". Because when upgrading a builtin 
package, the "current" version is not deleted.

So we need to compute the exact version to install (then package-install 
does not say "it's already installed" because the installed version is 
different). The use of package-install-from-archive might have been a 
mistake, though, (in case dependencies need to be updated too) I'm 
looking into that now.

Alternatively, we could add an optional argument to package-install 
which would mean "install the latest version anyway".

> > Just to be clear, we are talking about the 4 lines at the end, right?
>
> Yes, and also the (somewhat mysterious) additions of tests for
> pkg-desc.

pkg-desc is nil for builtin packages in this case (they are not in 
package-alist, so (assq package package-alist) returns nil).